Since trading Khalil Mack to the Chicago Bears, Jon Gruden has several times mentioned the Raiders' need for a pass-rusher.

According to a report, on Sunday, Gruden admired Mack picking up yet another strip-sack.

Mack has transformed the Bears into an elite defense while the Raiders struggle, and it's hard to think the deal could define Gruden's tenure in Oakland.

One month after the Oakland Raiders traded Khalil Mack to the Chicago Bears, the deal keeps re-surfacing with the man who helped make the trade, Jon Gruden.

In the month since the Raiders traded the star defensive end following a contract holdout neither side could resolve, Gruden has several times mentioned Mack outright or alluded to Mack's skill set.

After the Raiders Week 2 loss to the Denver Broncos, Gruden said the Raiders had to improve their pass rushing.

"We gotta do something [about the pass rush], we gotta do something," he said. "We gotta get there. We gotta win some one on ones, maybe call some more blitzes. We gotta figure something out. We will."

Later, he said it's "tough" to find good pass rushers.

"It's hard to find a great one. It's hard to find a good one. It's hard to find one ... So you've got to train these guys. It takes a little time to learn how to rush the passer."

Gruden, of course, had spent much of the first week after the trade discussing the deal and the Raiders' need to move on. He mentioned that players had to step up in Mack's absence. Gruden was talking about the players actually on the roster. Nonetheless, talking about the need for a pass rush after trading a former defensive player of the year struck many as ironic.

On Sunday, before the Raiders picked up their first win of the season, Gruden was even admiring Mack's performance as the Bears beat the Tampa Bay Buccaneers. Via NFL Network's Mike Silver:

"As he readied his game face for what he hoped would be his first NFL head-coaching victory in exactly nine years and ten months, Jon Gruden sat in the coaches' area of the home locker room at the Oakland Coliseum on Sunday morning, scrolled through his cell phone and got some decidedly disturbing news.

"'Damn — Khalil Mack had another strip sack?" Gruden asked rhetorically, shaking his head at the Oakland Raiders assistant coaches in his midst. 'Are you ... kidding me?'"

Indeed, Mack by himself has been better than the entire Raiders defense. Through four games, he has five sacks, four forced fumbles, an interception, and a defensive touchdown. He's graded as Pro Football Focus' No. 1 edge defender. He's transformed the Bears into an elite defense.

Meanwhile, the Raiders as a team have five sacks, three forced fumbles, and three interceptions, all while giving up 30 points per game.

It's early, but at 1-3, with overtime needed to get their first win of the season, the Raiders don't look like an elite team. It will take some time for Gruden to re-shape the roster to his liking, but it's hard not to view the Mack trade as the deal that will define his tenure.